(a) Field of the Invention
The present invention relates to a stable aqueous solution-type oxidizing agent composition consisting of an aqueous solution containing an oxidizing agent, which consists of ammonium nitrate as a main component and an inorganic chlorate, and further containing a phosphate as a stabilizer.
(b) Description of the Prior Art
It has hitherto been known that inorganic chlorate decomposes at high temperature and further its aqueous solution decomposes in the acidic region when in the presence of chlorine ions.
However, there has not been fully investigated the behavior at high temperature of an aqueous solution of an oxidizing agent consisting of ammonium nitrate as a main component and inorganic chlorate.
U.S. Pat. No. 3,282,753 specification discloses the use of sodium carbonate, sodium hydroxide or potassium hydroxide as a stabilizer for improving the storage stability at high temperature of a slurry explosive containing a solution of the above described oxidizing agent.
However, although the decomposition of inorganic chlorate in an explosive can be somewhat suppressed by these stabilizers, ammonium nitrate decomposes gradually to decrease its inherent action as an oxidizing agent. Moreover, in this slurry explosive, inorganic chlorate, ammonium nitrate and the like are dispersed in water to form a water gel, and therefore ammonium nitrate decomposes rapidly. Further, the inorganic chlorate and ammonium nitrate are present in a crystalline form, and therefore the inorganic chlorate decomposes rapidly. While, in a homogeneous aqueous solution of oxidizing agent, wherein ammonium nitrate and inorganic chlorate are completely dissolved in water, even when the above described stabilizer is used, it is difficult to prevent the decomposition of the inorganic chlorate, particularly its decomposition at high temperature, and further it is difficult to suppress the decomposition of ammonium nitrate.
The inventors have found that, when an aqueous solution of an oxidizing agent consisting of ammonium nitrate as a main component and an inorganic chlorate is formed into a very small droplet, that is, formed into a water-in-oil emulsion, the crystallization of the oxidizing agents of inorganic chlorate and ammonium nitrate can be suppressed and the decomposition of the oxidizing agents can be prevented, and have already filed a water-in-oil emulsion explosive composition, wherein the crystallization of the oxidizing agents is suppressed and the decomposition thereof is prevented (Japanese Patent Application No. 2,771/81).
However, although the above described water-in-oil emulsion explosive composition is stable after the explosive composition has been formed, the aqueous solution of the oxidizing agents used for the production of the explosive composition must be kept at high temperature during its storage in order to prevent the crystallization of the oxidizing agents, resulting in the decomposition of the inorganic chlorate. Therefore, the stability, particularly stability at high temperature, of the aqueous solution of the oxidizing agent is still insufficient.
The inventors have made various investigations with respect to the stabilization of an aqueous solution of an oxidizing agent which consists of ammonium nitrate as a main component and an inorganic chlorate, and found out that, when a specifically limited stabilizer is added to the solution, the decomposition of ammonium nitrate does not occur, and the decomposition of the inorganic chlorate is suppressed even at high temperature, and further the stabilizer-containing aqueous solution of the oxidizing agent is sufficiently stable even in the presence of chloride ions, to accomplish the objects of the present invention.